Closure device

Abstract: A flap 10 has a first portion 11 flexibly connected to a lid 2 and a second portion 13 connected to the first portion 11 by an integral flexible hinge strip 14. The second portion also 13 carries pivot pins 15 which locate into an upstanding rim 16 of the lid portion 2. These pivot pins are slightly offset vertically and horizontally from the flexible hinge 14 thus enabling the flap 10 to be toggled between two stable conditions. In the first of these the hinge 14 is snapped to a position above the pivot pins 15 thus pressing the second flap portion 13 positively down into the opening 6. If pressure is applied to the first portion 11 the flexible hinge 14 will be forced down past and below the pivot pins 15 thus causing the second flap portion 13 to flip upwardly into the alternative stable condition.

Description: This invention is concerned with devices for creating a secure closure to an opening in a container. A closure device in the form of a simple lid with a central hinge, which is pivotally connected at one edge to the top face of a cap for a container is disclosed in U.S. Patent 4223814. One half of the lid can be pressed into a recess so that the other half lifts above the central hinge to expose openings in the top of the cap. The hinging arrangement is very simple and uncontrolled. For the present invention the container may, for example, be one which is intended to hold sharps (hypodermic needles and the like) and surgical and medical waste. The closing of such a container needs to be very positive and not susceptible to accidental opening. The closure arrangement of U.S. Patent 4223814 is unsatisfactory for this purpose as there is no positive closure and accidental opening is very possible. According to the present invention there is provided a container closure device for an opening defined by a rim of a lid portion of a container, and comprising a flap flexibly connected at one end to the lid portion and having first and second portions respectively on opposite sides of a hinge which is located on the lid portion, wherein the first flap portion is nearest said flexible connection and forms an actuating member for the hinge, and the second flap portion is furthest from said flexible connection and is positioned to close off said opening when the hinge is in one condition, and is positioned fully to reveal said opening when the hinge is in an alternative condition, characterised in that the hinge is a snap action hinge which has two stable conditions, and comprises a pivot connection defined by pins on the lid portion locating into holes in said rim, and a flexible hinge across said first flap portion, the flexible hinge being located close to the pivot connection but along a line which is displaced away from the axis of the pivot connection towards said flexible connection, and is also displaced above said axis when the hinge is in said first condition but below said axis when the hinge is in said second condition. With such an arrangement the snap action hinge will hold the second flap portion securely in place over the opening in the lid portion until such time as suitable positive pressure is applied to the first flap portion to toggle it into its other stable condition. Ideally the flexible connection and the flexible hinge are integrally moulded thinner portions of a moulded plastics flap and lid portion combination. The flexible hinge (and indeed the flexible connection) then takes the form of what is commonly termed a "living hinge". Preferably, a recessed part of the lid portion receives the first flap portion in either of its two operating positions. Advantageously the underside of the first flap portion within this recessed part can then incorporate ribs which angle down from the flexible hinge into the recess towards said flexible connection. The lower ends of the ribs then act as pressure points on the recessed part as a second flap portion is pushed down and the sloping lower faces of the ribs seat the second flap portion into the base of the recessed part in the other stable condition of the hinge with the first flap portion raised in the open condition. It is preferable that there should be a locking device operable to prevent operation of said snap action hinge. This locking device can comprise one or more movable tabs which can be adjusted to lie below the first flap portion near to the flexible hinge. Locking can be made more or less reversible by providing that the or each tab is movable into its locking position into engagement with a holding formation on the lid portion and/or the first flap portion for resisting return movement of the tab. For many uses it may be desirable to provide that the underside of the second flap portion carries a resilient sealing pad for sealing engagement over the opening in the lid portion. In some instances it is desirable to provide the lid portion with an upstanding rim around the whole of the flap when the flap is in its closed position. Such a rim may, however, be disadvantageous if the container is to incorporate substances which are intended to be poured out. The invention may be performed in various ways and a preferred embodiment will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a perspective view of a container incorporating a closure device of this invention; Figure 2 is a vertical section through the combination of the container with the lid portion incorporating parts of the closure device; Figure 3 is a plan view of the parts of the lid and closure device as shown in Figure 3; Figures 4 and 5 are vertical longitudinal sections through the lid of the container of Figure 1 showing the closure device respectively in the closed and open conditions; and Figures 6 and 7 are cut-away portions of part of the lid and closure device as shown in Figure 6 to indicate certain locking features. The container illustrated in Figures 1 to 3 comprises a base portion 1 onto which is fitted a lid portion 2. A strap handle 3 has a enlarged end 4 which fits into a slot 5 in a side wall of the base 1. This handle can then be slid between a carrying position and a flattened storage position. The lid 2 has an opening 6 formed in the top surface thereof providing access to the interior of the base 1 via a chute 7. The lid and base are fitted together by interlocking engagement portions 8 and 9. The closure device is provided by a flap 10 formed from a first portion 11 which is flexibly connected to the lid 2 by an integral strip 12 of the plastics moulding from which the lid is formed. A second portion 13 of the flap 10 is connected to the first portion 11 by an integral flexible hinge strip 14. As can be seen particularly from Figures 2 to 5 the second portion 13 carries pivot pins 15 which locate into holes at either side of an upstanding rim 16 of the lid portion 2. These pivot pins are slightly offset vertically and horizontally from the flexible hinge 14 thus enabling the flap 10 to be toggled between two stable conditions. The first of these is illustrated in Figure 4 where the hinge 14 is snapped to a position above the pivot pins 15 thus pressing the second flap portion 13 positively down into the opening 6. If pressure is applied to a region generally indicated at 17 in Figure 4 the flexible hinge 14 will be forced down past and below the pivot pins 15 thus causing the second flap portion 13 to flip upwardly into the stable condition illustrated in Figure 5. Angled ribs 18 at the lower surface of the first flap portion 11 give added strength to that portion 11 and also act to limit the extent to which the flap portion 11 can be pressed down onto the base wall 19 of a recessed part 20 of the lid 2. The first flap portion 11 can be locked into the raised position of Figure 4 by means of tabs 21 in the side walls of the lid 2. As each tab 21 is pushed inwardly it rides up over a wedge 22 on the wall 19 and also slides along a wedge 23 on the under face of the flap portion 11 until it locates into a notch 24 in the wedge 23. The tabs 21 then prevent the flap portion 11 from being pressed downwardly to open the other portion 13 of the flap 10 and the tabs 21 are locked in place and cannot readily be restored to their original condition. Thus the container can be sealed against further opening. The closure device shown in the drawings has been developed essentially as a receptacle for sharps and medical waste products. The closure portion 13 of the flap 10 carries, on its lower face, a layer of a resilient sealing material 25 (such as rubber). This will be pressed firmly down onto the perimeter of the opening 6 to seal against loss of the contents, particularly liquids. The chute 7 also makes it difficult for the contents to reach the opening 6 even if the container is turned upside down. If the closure device is to be used for temporary closure of, for example, a container for washing powder where the objective is that the contents should be capable of being poured out, then the chute 7 would be omitted so that the contents have direct access to the opening 6 when the container is tipped. Also the rim 16, at least in the region where it surrounds the opening 6, should ideally be omitted so as not to provide an obstruction to pouring.

Claims: A container closure device for an opening (6) defined by a rim (16) of a lid portion (2) of a container (1), and comprising a flap (10) flexibly connected at one end to the lid portion and having first (11) and second (13) portions respectively on opposite sides of a hinge (14) which is located on the lid portion, wherein the first flap portion (11) is nearest said flexible connection (12) and forms an actuating member for the hinge, and the second flap portion (13) is furthest from said flexible connection and is positioned to close off said opening when the hinge is in a first condition, and is positioned fully to reveal said opening when the hinge is in a second condition, characterised in that the hinge is a snap action hinge which has two stable conditions, and comprises a pivot connection defined by pins (15) on the lid portion locating into holes in said rim, and a flexible hinge (14) across said first flap portion, the flexible hinge being located close to the pivot connection (15) but along a line which is displaced away from the axis of the pivot connection (15) towards said flexible connection, and is also displaced above said axis when the hinge is in said first condition but below said axis when the hinge is in said second condition. A device according to Claim 1, wherein a recessed part (19) of the lid portion receives the first flap portion. A device according to Claim 2, wherein the underside of the first flap portion within said recessed part carries ribs (18) which angle down from the flexible hinge into the recess towards said flexible connection. A device according to any one of Claims 1 to 3, including a locking device (21) operable to prevent operation of said snap action hinge. A device according to Claim 4, wherein the locking device comprises at least one tab (21) which is adjustable from a non-interfering position to lie in a locking position below said first flap portion (11) near to said flexible hinge so as to restrict any downward pivoting movement of the first flap portion. A device according to Claim 5, wherein the tab in its locking position engages a holding formation (22,23) on the lid portion and/or said first flap portion for resisting return movement of the tab. A device according to any one of Claims 1 to 6, wherein the opening is at the mouth of a chute (7) leading down into the container clear of the container walls. A device according to any one of Claims 1 to 7, wherein the flexible connection and the flexible hinge are integrally moulded thinner portions of a moulded plastics flap and lid portion combination. A device according to any one of Claims 1 to 8, wherein the underside of said second flap portion carries a resilient sealing pad (25) for sealing engagement over the opening in the lid portion. A device according to any one of Claim 1 to 9, wherein the lid portion has an upstanding rim (16) around the whole of the flap when the flap closes.

Inventors: HARRIS JOHN, HARRIS, JOHN
Applicants: FRONTIER PLASTICS LTD, FRONTIER PLASTICS LIMITED
Application year: 1994
Main classification: B65D47
IPC codes: A61M5, A61G12, A61J1, C04B28, B65D47, B65D43